SU1666193A1 - Cyclone for separating sticking dust - Google Patents

Abstract

The invention relates to devices for cleaning gas from dust and improves the efficiency of gas cleaning from dust and reduces energy costs. Chain beads 5 upper ends are suspended from the lid 7 of the housing 1 along the inner surface made of antiadhesive material, the lower end of each previous chain bend is attached to the base of the body at an angle of attachment of the upper end of the subsequent chain bead, and L≥ϕD / N + H where L is the chain length

N is the number of chains

D - cyclone diameter

H - the height of the cyclone, a device for regeneration is made in the form of a gate on the exhaust pipe. 3 il.

Description

FIG, g

The invention relates to devices for cleaning gas from dust and can be used in various sectors of the national economy.

The purpose of the invention is to increase the efficiency of gas cleaning from dust and reduce energy consumption.

Figure 1 shows a cyclone section; figure 2 - section aa in figure 1; Fig. 3 is a scan of the cyclone cylindrical body with hanging chain beads (the dashed lines indicate the position of the chains when the cyclone operates).

The cyclone comprises a housing 1, the inner surface 2 of which is made of anti-adhesive material with a tangential inlet 3 and an axial exhaust 4 branch pipes. Chain beads ndy 5 are suspended from the upper ends 6 to the housing cover 7. The lower end 8 of each previous chain link is fixed to the base 9 of the body under the mount 10 of the upper end of the subsequent chain link. A device for regeneration is made in the form of a gate 11 mounted on the exhaust pipe. The base of the cyclone body is connected to the dust collecting bin 12.

The cyclone works as follows. Dust gas at the inlet 3 is introduced into the housing 1, where the gas flow under the action of centrifugal forces is thrown to the surface 2 of the housing 1. In this case, part of the dust adheres to the surface 2 due to high adhesion, and the other part is transported in a hopper 12 by the dusty gas The purified gas through the exhaust duct 4 is released into the atmosphere or enters the next gas cleaning unit. In such an operating mode of the cyclone, the vortex flow, due to the high tangential velocity (up to 25 m / s in cyclones), draws and presses the arms 5 to the surface 2 of the housing 1 (position 2 in FIG. 3). During a certain period of operation, a layer of dust builds up on the surface 2 of the housing 1. The hydraulic resistance of the cyclone increases. To regenerate the surface 2 of the housing 1, the gate 11 is moved (manually or by means of an electric drive), which is in the Open position during operation of the cyclone. When the exhaust pipe 4 is partially closed or partially blocked, the speed of the vortex flow inside the housing 1 decreases, its weighting capacity (ability to hold the chain beads 5 in the state of pressing towards the surface 2 of the housing 1 - F, position 2) decreases and the chain beads ndy 5 falls under the action of its own weight, i.e. come to position 1 (fig.Z).

When opening the gate 11 - an increase in the cross section of the exhaust pipe 4. Speed

the vortex flow increases to the same magnitude, with the result that the chain beads 5 are set in motion along the surface 2 of the housing 1 (the movement from position 1 to position 2), while removing the adhering

dust. Anti-adhesive coating, for example, of polyethylene, the surface 2 of the housing 1 reduces the adhesion force, ensuring effective cleaning of the cyclone from dust deposits.

The movement of chain beads nd 5 from position 1 to position 2 is ensured by the weighting capacity of the vortex flow, which increases with increasing sizes of chain links (i.e., increases

windage of chained sleeves nd 5). An increase in the sail area of the chained beads 5 leads to the intensification of the movement of the latter in the course of regeneration, and, consequently, to an effective cleaning of the surface 2 of the body 1 from dust deposits. However, an increase in the size of chain beads nd 5 leads to an increase in their weight, which reduces the weighting effect of the vortex flow on the bends 5, and also leads to an increase in

violation of the aerodynamics of the cyclone flow inside the housing 1, and all this reduces the efficiency of gas cleaning from dust and increases the hydraulic resistance of the cyclone. Therefore, instead of steel chains

It is preferable to use chains of lighter materials (aluminum, titanium), which allows for the necessary intensity of regeneration movement of chain beads with a smaller size.

links (with a smaller sailing surface).

The number of chain beats is determined for each type of cyclone experimentally, taking into account the optimum

5 fictitious speeds. Studies show that the optimal fictitious speed for countercurrent cyclones is in the range of 2.5-4.5 m / s and depends on the type of cyclone. The length of the chain selected from the condition

- 4- N, provides regeneration

the entire surface in the zone of the chain with the minimum length of the latter. The length of the bridge is greater than the value --- + H (in

% EP

within 10%) to ensure the regeneration of the upper sections of the chain of action (at the cyclone cover) for cyclones with direct injection of dust and gas flow (the axis of the input

nozzle perpendicular to the central axis of the cyclone).

Gate 11 is preferably installed on the exhaust manifold, where the purified gas flows, since when installed in a different place - at the inlet manifold, it may overgrow with sticking dust.

The proposed device was tested for cleaning a vapor-dust gas stream with a flow rate of 1500 m3 / h. Cyclone 400 mm, the surface of its body is made of thick-walled polyethylene (d 15 mm). For regeneration, chain beads made of aluminum (p 2.7 kg / m, with a size of links of 30-40 mm, from a rod with a diameter of 3-4 mm were used. Quantity - 4 pcs. (More chain beads led to an increase in hydraulic resistance). and a decrease in the efficiency of cleaning the dust and gas flow from dust, and a smaller amount of beads led to a decrease in regeneration due to an increase in the mass of the circuit).

Other parameters of dust and gas flow

Temperature, ° С Relative humidity of the stream,

%

Dust concentration

flow, g / m3 Tangential velocity of a vortex flow, m / s Length of chains composition

,

0.4

+ 1.2-1.6m,

where I is the chain length.

After an hour of operation, the thickness of the dust layer was 0.6 m. Effective regeneration was provided by 3 open-to-3-slider cycles. In the process of operation of the cyclone, tensioned chain beats h5

10 5 0

Under the influence of turbulent pulsations of the cyclone flow, the waves were in a state of vibration, as a result of which their ingrowth into the thickness of dust deposits was excluded. The polyethylene surface of the casing has a high thermal insulating ability, as a result of which the vapor condensation from the gas flow was practically excluded, which reduced the strength of sticking of dust particles. The flow cleaning efficiency was 94%; hydraulic resistance was 1650 Pa.

Compared to the prototype, the efficiency of the proposed cyclone is increased by 8%, i.e. dust emission to the atmosphere is reduced by a factor of 2, and hydraulic resistance is reduced by 230 Pa.

Claims (1)

Claims of the invention Cyclone for trapping sticking dust, including a housing with a lid, inlet and exhaust nozzles, chain beads, a device for regeneration, a dust collecting bin, characterized in 5 in order to increase the efficiency of gas cleaning from dust and reduce energy consumption, the upper ends of the chains the gearbox is attached to the housing cover, the lower end of each previous chain linkage is fastened at the base of the case under the fixing unit of the upper end of the follower chain, and the length I of the chain linkage is determined by rmule 5 I + H, where D is the diameter of the cyclone body; n is the number of chain beads; 0 Н - height of the cyclone body; the inner surface of the body is made of anti-adhesive material, and the device for regeneration is made in the form of a gate mounted on the exhaust 5 pipe. Aa Fie.2 Position2 / Position 1 Fm.z W